I'd say battery first, thats an old battery. You already have a good size alt for that system. The big 3 is an option, but I bet money if you put a fresh battery in it you'll notice a big difference.
I would like to retract my statement about the order of the upgrades after looking and seeing you still have the original battery in the truck. I agree with this. The battery should be the first thing you upgrade. 5 years is pretty much the end of a battery's life, especially if you've been running a system on it.
Thank you for the help, tomorrow I will buy a new yellowtop battery and see what happens, If I still have trouble, well, then with my next weeks paycheck I will buy wire and do the big 3. Thanks